Such water treatment units for use in water piping networks are known in the state of the art, for instance in U.S. Pat. No. 3,974,071. This document describes a water treatment unit with a metallic casing in which a reacting anode is placed, spirally wound along the direction of the flow. The spiral form is to create a close contact between the water and the surface of the anode.
The effect of such water treatment units is based on an electrogalvanic principle in which a conducting connection between two non-similar metals, due to the different values of these metals, causes one of the metals as the reacting anode to release its metal ions into the water. It has been shown that such metal ions release causes positive effects, for instance by building up an anti-corrosion layer on the pipe interior of a water piping network in which such a water treatment unit is contained.
It has likewise been observed that the release of metal ions leads to an agglomeration of substances contained in the water, for instance scale forming substances, which results in a particle size of these substances that is larger by comparison to untreated water—presumably due to seeding on the metal ions. Particularly due to the enlargement of the substances in the water due to agglomeration, fewer of these substances can deposit themselves in the subsequent regions of the water piping network, so that a water piping network which possesses such a water treatment unit will keep its effective interior pipe diameter free of deposits. Without such a water treatment unit, there is a recognizable tendency for water pipes to gradually grow shut inside, from the outer edge towards their center, for instance due to calcium deposits.